3 ms·
One half-millionth is 2 ppm. Half of one-millionth is 0.5 ppm. Wikipedia says the concentration is 5.2 ppm.
by logfromblammo 10y ago
One half-millionth is 2 ppm. Half of one-millionth is 0.5 ppm. Wikipedia says the concentration is 5.2 ppm.
loading thread…